Performance on visual perception and visual cognition tasks depends critically on precise spatiotemporal deployment of attention. In order to help guide therapeutic interventions for patients with perceptual and/or cognitive deficits, it is critical to develop a detailed understanding of the brain circuits and mechanisms that support attentional function. Although cerebellar dysfunction has been implicated in attention-deficit / hyperactivity disorder (ADHD), potential contributions of the cerebellum to visual attentional functions have largely been overlooked. Cerebellar dysfunction is also implicated in other neurological disorders such as schizophrenia, obsessive-compulsive disorder and autism. In the motor system, the cerebellum is known to play a key role in fine temporal coordination of movements. Moreover, the cerebellum appears to form `internal models' of learned tasks that can be used to correct errors `on the fly,' and thus support efficient task performance. Recent evidence indicates that specific sub-regions of the human cerebellum exhibit functional connectivity with specific cortical networks, forming cerebro-cerebellar networks. Although the motor cerebro- cerebellar network has been well studied, the functional properties of cerebro-cerebellar networks linked to cognition have received only modest scientific attention. Our preliminary results demonstrate that cerebellar lobules VIIb/VIIIa are a component of a cerebro-cerebellar `dorsal attention network' that supports sustained visual attention and visual working memory. Here, we plan to explore this network and other potential cerebellar sub-region contributions to established cortical attention networks, including the ventral attention network and the cognitive control network. The demonstration of the existence of multiple cerebro-cerebellar attention networks and the elucidation of distinct cerebellar functional contributions to different forms of attention would significantly advance both our understanding of attention networks in the brain and our understanding of the functional roles of the cerebellum in these networks. We will also examine specific hypotheses regarding the mechanisms by which cerebellar lobules VIIb/VIIIa contribute to visual attention and visual working memory performance. This knowledge can guide the development of assays that can refine diagnosis and treatment of neurological disorders in which visual attention and cognition are impaired. It may also help to identify approaches for maintaining cognitive function in persons experiencing disease-related or age-related decline.